will have or would have

 

We use the perfective will have when we are looking back from a point in time when something will have happened.

By the end of the decade scientists will have discovered a cure for influenza.
I will phone at six o’clock. He will have got home by then.

or looking "back" from the present:

Look at the time. The match will have started.
It’s half past five. Dad will have finished work.

We use would have as the past tense form of will have:

I phoned at six o’clock. I knew he would have got home by then.
It was half past five. Dad would have finished work.

We use would have in past conditionals to talk about something that did not happen:

If it had been a little warmer we would have gone for a swim.
He would have been very angry if he had seen you.
 

Exercise

Comments

Hi,

Can you please tell me the difference between these sentences and tell me which is right

1. The chemistry values have populated.

2. The chemistry values have been populated.

Thanks in advance!

Hello Herr_Kiki,

The first sentence has a verb in the present perfect in the active voice, and the second is the same except that it is in the passive voice. I'd say the first is incorrect, but that really depends on what exactly the sentence means, which is unclear to me.

Best regards,
Kirk
The LearnEnglish Team

hi :) i'm a little confused... please help :)

is this correct: I carefully thought this through and sincerely regret that I would have to pass up the opportunity.

or is this better: I carefully thought this through and sincerely regret that I have to pass up the opportunity.

thanks so much :)

Hi y5y3n,

I'd recommend the second sentence, but with the present perfect instead, though exactly how you should say it really depends on the context:

'I have carefully thought this through and sincerely regret that I have to pass up the opportunity' (I've thought about it and have decided not to accept)

'I carefully thought this through and sincerely regret that I have had to pass up the opportunity'. (I thought about it and have already declined the offer)

I hope this helps.

Best wishes,
Kirk
The LearnEnglish Team

Hi,

Why do they use "were" when it is used along with plural? Please explain.

e.g. I would buy that computer if it were cheaper.

In that (above mentioned) example, computer is 'singular' and it should be like "I would buy that computer if it was cheaper.", correct?

Thank you.

Hi PrashantK,

You are correct that normally we use a singular verb after 'it'. However, in condition sentences we can follow 'if' with were, even with a singular noun. That is why we say (as in the song) 'If I were a rich man...' rather than 'If I was...'. In all of these examples 'was' is also correct, but 'were' is more common, I would say.

Best wishes,

 

Peter

The LearnEnglish Team

Hello,
I put the following two sentences on Google to check which one is correct, but both of them were there, so I wonder if both are correct; and what is the difference between them in case both are correct?
" I would have helped you if I had been there."
" I would have helped you if I were there."

Hello zagrus,

The first sentence is an example of the third conditional, and the second of a mixed conditional. Both of these constructions are explained on our Conditionals 2 page. If the difference between them is still unclear after reading that page, please ask us again there.

Best regards,
Kirk
The LearnEnglish Team

Hello,
I checked the link above, but still the exact meaning of the second sentence, which is "I would have helped you if I were there.", is not clear for me. So, would you please tell me its meaning and in what condition it should be used ?

Thanks in advance

Hi zagrus,

This sort of mixed conditional is relatively unusual and is explained in some detail on this BBC page. Looking at the sentences you ask about more carefully now, I'd recommend avoiding the mixed conditional version - the third conditional version is much clearer.

Best regards,
Kirk
The LearnEnglish Team

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